Buggy code:
public class ToStringBuilder { private static ToStringStyle defaultStyle = ToStringStyle . DEFAULT_STYLE ; public static ToStringStyle getDefaultStyle ( ) { } public static String reflectionToString ( Object object ) { } public static String reflectionToString ( Object object , ToStringStyle style ) { } public static String reflectionToString ( Object object , ToStringStyle style , boolean outputTransients ) { } public static String reflectionToString ( Object object , ToStringStyle style , boolean outputTransients , Class reflectUpToClass ) { } public static void setDefaultStyle ( ToStringStyle style ) { } private final StringBuffer buffer ; private final Object object ; private final ToStringStyle style ; public ToStringBuilder ( Object object ) { } public ToStringBuilder ( Object object , ToStringStyle style ) { } public ToStringBuilder ( Object object , ToStringStyle style , StringBuffer buffer ) { } public ToStringBuilder append ( boolean value ) { } public ToStringBuilder append ( boolean [ ] array ) { } public ToStringBuilder append ( byte value ) { } public ToStringBuilder append ( byte [ ] array ) { } public ToStringBuilder append ( char value ) { } public ToStringBuilder append ( char [ ] array ) { } public ToStringBuilder append ( double value ) { } public ToStringBuilder append ( double [ ] array ) { } public ToStringBuilder append ( float value ) { } public ToStringBuilder append ( float [ ] array ) { } public ToStringBuilder append ( int value ) { } public ToStringBuilder append ( int [ ] array ) { } public ToStringBuilder append ( long value ) { } public ToStringBuilder append ( long [ ] array ) { } public ToStringBuilder append ( Object obj ) { } public ToStringBuilder append ( Object [ ] array ) { } public ToStringBuilder append ( short value ) { } public ToStringBuilder append ( short [ ] array ) { } public ToStringBuilder append ( String fieldName , boolean value ) { } public ToStringBuilder append ( String fieldName , boolean [ ] array ) { } public ToStringBuilder append ( String fieldName , boolean [ ] array , boolean fullDetail ) { } public ToStringBuilder append ( String fieldName , byte value ) { } public ToStringBuilder append ( String fieldName , byte [ ] array ) { } public ToStringBuilder append ( String fieldName , byte [ ] array , boolean fullDetail ) { } public ToStringBuilder append ( String fieldName , char value ) { } public ToStringBuilder append ( String fieldName , char [ ] array ) { } public ToStringBuilder append ( String fieldName , char [ ] array , boolean fullDetail ) { } public ToStringBuilder append ( String fieldName , double value ) { } public ToStringBuilder append ( String fieldName , double [ ] array ) { } public ToStringBuilder append ( String fieldName , double [ ] array , boolean fullDetail ) { } public ToStringBuilder append ( String fieldName , float value ) { } public ToStringBuilder append ( String fieldName , float [ ] array ) { } public ToStringBuilder append ( String fieldName , float [ ] array , boolean fullDetail ) { } public ToStringBuilder append ( String fieldName , int value ) { } public ToStringBuilder append ( String fieldName , int [ ] array ) { } public ToStringBuilder append ( String fieldName , int [ ] array , boolean fullDetail ) { } public ToStringBuilder append ( String fieldName , long value ) { } public ToStringBuilder append ( String fieldName , long [ ] array ) { } public ToStringBuilder append ( String fieldName , long [ ] array , boolean fullDetail ) { } public ToStringBuilder append ( String fieldName , Object obj ) { } public ToStringBuilder append ( String fieldName , Object obj , boolean fullDetail ) { } public ToStringBuilder append ( String fieldName , Object [ ] array ) { } public ToStringBuilder append ( String fieldName , Object [ ] array , boolean fullDetail ) { } public ToStringBuilder append ( String fieldName , short value ) { } public ToStringBuilder append ( String fieldName , short [ ] array ) { } public ToStringBuilder append ( String fieldName , short [ ] array , boolean fullDetail ) { } public ToStringBuilder appendAsObjectToString ( Object object ) { <START_BUG> ObjectUtils . appendIdentityToString ( this . getStringBuffer ( ) , object ) ; <END_BUG> return this ; } public ToStringBuilder appendSuper ( String superToString ) { } public ToStringBuilder appendToString ( String toString ) { } public Object getObject ( ) { } public StringBuffer getStringBuffer ( ) { } public ToStringStyle getStyle ( ) { } @ Override public String toString ( ) { } }

Fix:
ObjectUtils . identityToString ( this . getStringBuffer ( ) , object ) ;